Optical Characterization of a Semisolid Membrane by High Speed Interferometry David Asael Gutiérrez Hernández*, Carlos Pérez López, Fernando Mendoza Santoyo Centro de Investigaciones en Óptica. Lomas del Bosque 115. Col. Lomas del Campestre. C.P. 31715. León, Guanajuato, México. Juan Arturo Aranda Ruiz Unidad Profesional Interdisciplinaria de Ingeniería campus Guanajuato. Instituto Politécnico Nacional. Av. Mineral de Valenciana No. 200 Col. Fracc. Industrial Puerto Interior, C.P. 36275. Silao de la Victoria, Guanajuato, México. Daniel D Aguayo Laboratory of biomedical Physics, University of Antwerp. Groenenborgerlaan 171, B2020, Antwerpen, Belgium * Corresponding author: davidgh@cio.mx Abstract In this paper we present a high speed electronic speckle pattern interferometer (HSESPI) for the experimental analysis of a semisolid and rectangular membrane fully supported on its 4 edges. This system is based on an out of plane interferometer setup that integrates a continuous wave and a fast camera with an acquisition rate of 5000 frames/s. The acquired data is a serie of temporal and full-field spatial samples of the surface deformation which have an optical phase change due to free vibrations coming from an external and random vibration frequency. Several fringe patterns of interference are contended all over the 5000 recorded frames. Each fringe pattern is processed by a phase extraction of a single fringe pattern algorithm. With this information it is possible to do a spatiotemporal characterization of the membrane. The results shown graphics of a couple of points of the membrane followed along the time and the spatial evolution of a couple of profiles inside the membrane. Keywords: High Speed ESPI, membranes, transient vibrations. OCIS codes: (120.6165) Speckle interferometry, metrology, (120.3180) Interferometry, (120.5050) Phase measurement, (120.7280) Vibration analysis.